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U20 Headers

Posted: Wed Jan 25, 2023 10:53 pm
by Andrew Griffith
:smt006
I'm looking to buy a U20 header that fit the example of the pics I included. Unfortunately the owner of the pic will not sell. Maybe a possible lead to who might have info. Andrew

Re: U20 Headers

Posted: Wed Jan 25, 2023 11:41 pm
by Daryl Smith
Irrelephant

Re: U20 Headers

Posted: Thu Jan 26, 2023 3:25 am
by Andrew Griffith
Daryl it is a racing header and yes it's a U20 head. It was designed back in the 60tys but was used for quite some time..but just racing. It comes out under the frame and one tube over the frame to exit on the left side under the body and then dumped right in front of the left rear tire .

Re: U20 Headers

Posted: Thu Jan 26, 2023 3:27 am
by Andrew Griffith
I'll have to get with you about the megasquite fuel injection and your thoughts on it..thanks Andrew

Re: U20 Headers

Posted: Thu Jan 26, 2023 9:12 am
by theunz
Here’s a link about some headers made in Australia which are highly regarded. These are quite expensive especially when you add in the shipping. Keep in mind that the best headers in the world won’t make much difference unless the whole engine is designed around them. Another thing to consider is where they make their power. Giving up low and mid range just to have screaming power at 6,000 plus rpm’s is not going to be fun on a street driven car.
viewtopic.php?t=31823

Re: U20 Headers

Posted: Thu Jan 26, 2023 11:40 am
by spl310
That looks similar to the BRE header. They are tough to find

Re: U20 Headers

Posted: Thu Jan 26, 2023 12:25 pm
by Andrew Griffith
Yes it is BRE style header. I can have one made but its pricey. It's been dynoed and on that engine it was worth 14hp. I'm building a pretty radical stroker u20 and this style header is going to be for a higher rpm range then 6000. It's also exits out of the car frame and 1 tube over the top of the frame to end exiting at the left rear tire..also adding to the vintage direction for the build. I will probably have to have it fabricated. Andrew

Re: U20 Headers

Posted: Thu Jan 26, 2023 2:10 pm
by Daryl Smith
Not exactly cheap anymore, but, this program is about as good as it gets for header design - for proper length, diameter, and style of header (4-1 or 4-2-1).
http://maxracesoftware.com/PipeMaxPro400.htm

Use the program to calculate the design parameters of the header to your horsepower and rpm goals. FWIW, it's been recommended for 8,000 rpm and lower a 4-2-1 header would be best, and consistently over 8000 rpm go to a 4-1.
For road racing, how much of your time is spent over 8,000 rpm?
The way I see it, very, very few roadsters would benefit from a 4-1 header.

The stock exhaust manifold was 'sort of' a 4-2-1 with cylinders 2 & 3 combined into one pipe immediately off the head, no real 'tuning' done there.

Re: U20 Headers

Posted: Thu Jan 26, 2023 4:55 pm
by Andrew Griffith
All great info..I will do my do diligence..as the engine is going to be pretty involved. Over 8000rpm for road racing and will be a stroker. But very much agreed every engine is different depending on the build. Thank you very helpful. Andrew

Re: U20 Headers

Posted: Thu Jan 26, 2023 9:15 pm
by Mike Unger
Andrew Griffith wrote: Thu Jan 26, 2023 4:55 pm All great info..I will do my do diligence..as the engine is going to be pretty involved. Over 8000rpm for road racing and will be a stroker. But very much agreed every engine is different depending on the build. Thank you very helpful. Andrew
Andrew,

If you plan on vintage racing there are certain things that are not allowed so I would build the car to the rule set so you have plenty of places to race. If you have any questions let me know.

Mike

Re: U20 Headers

Posted: Fri Jan 27, 2023 12:59 pm
by Daryl Smith
Irrelephant

Re: U20 Headers

Posted: Fri Jan 27, 2023 2:43 pm
by Andrew Griffith
Thanks Daryl

Re: U20 Headers

Posted: Fri Jan 27, 2023 5:01 pm
by Alvin
Try contacting Les Cannaday at Classic Datsun Motorsports in SoCal, he might have one or know where to locate.
Image
Image

There are also several examples of custom made BRE-style headers here on 311s, from user "gtrbg":
Image

Re: U20 Headers

Posted: Sun Jan 29, 2023 11:42 am
by tangoterje
Wow… let’s hope those engine mount insulators are in good shape!

Re: U20 Headers

Posted: Thu Feb 02, 2023 2:59 pm
by Andrew Griffith
Thanks for all the information..I do appreciate it and from knowledgeable people familiar with these cars..Andrew